As you can see from the error it looks like you are connecting project files that were ugpraded to 8.2 to a database that is version 8.0.
In this case I would recommend to roll back the backups and repeat the upgrade 7.0 -> 8.0

I am confused here, I ran the upgrade.exe to upgrade kentico 7 to 8.
How is that possible it upgraded to kentico 8.2. Please let me know the from where i can get the correct upgrade exe to ugrade it again.

Here is the description of our project - We have developed eCommerce website on kentico 7 with customization and created custom document type for product with transformation. I was getting lot of errors in transformation because kentico use different API for existing methods/property. I have made the changes
still i am getting below errors. I appreciate if you help me out.